Process of manufacturing lubricating oils



PATENT OFFICE.

JAMES WEIR, OI FILLMORE, CALIFORNIA.

PROCESS OF MANUFACTURING LUBBICATTNG OILS.

No Drawing.

To all whom it may concern:

Beit known that I, JAMES W. WEIR, a citizen of the United Statesresiding at Fillmore, Ventura Count California, have invented a new andusefu Process of M anufacturing Lubricating Oils, of which the followingis a specification.

In my copendmg applications Serial No, 545,438, for method ofmanufacturing lubricating oils, filed March 21, 1922, issued December 8,1925, patent No. 1,564,501, and Serial No. 30,356, for process ofrfining mineral lubricating oils, filed May 14, 1925, there aredescribed processes for refining lubricating oils in which thelubricating oil, after a sulfuric acid treatment and a removal of themajor portion of the resultant sludge, is commingled with a comminutedsolid adsorbent material to decompose the sludge remaining in the oil sothat the sand sludge may be removed by the adsorbent material. By suchprocess it is possible to neutralize the oil after. the acid treatmentwithout the usual caustic soda treatment.-

The present invention relates to an improvement upon the methods of suchcopending a plications, and is directed to cer tain modi cations in themethod of treating lubricating oil described therein, by which it hasbeen found that certain different and new results in the manufacture oflubricating oils can be obtained.

It is found that certain lubricating oils contain compounds andimpurities, particularlv organic acids, which must be removed if thebest grade of lubricating oil is to be obtained. Organic acids, forexample, are encountered in lubricating oils un er the followingconditions: (1) They occur naturally in certain crude petroleums; (2)they may be produced by decomposition of crude petroleum or its productsduring distillation; and (3) they may be produced by treatment oflubricating oils with. mineral acids.

, It is an object of the present invention to provide for the mostefficient removal of such organic acids and other impurities in aprocess in which the final neutralization of the refined lubricatingstock is carried out by the neutralizing methods of such copendingapplications. By such process, I am enabled not only to provide alubricating oil free from impurities such as organic acids, but am alsoenabled to provide from naphthenic base crude lubricating oils -whichApplication filed November 9, 1925. Serial No.- 68,009.

have been heavil acid treated and thus thoroughly refine a lubricatingoil which is free from compounds imparting to the oil a bluefluorescence and thus are markedly improved lubricants over those nowgenerally produced.

Various other objects and advantages of the present invention will beapparent from the following detailed description of an example of aprocess embodying the invention.

The lubricating oil stock is first treated with sulfuric acid in anypreferred or customary manner. The lubricating oil stock may be adistillate of any crude, either paraffin or naphtheni base, or mixedbase; The first treatment with acid is preferably conducted so as toremove the majority of the undesirable acids from the lubricating oilstock, .and this preliminary or first acid treatment may be carried outby the addition of the acid in several successive portions to the oilstock, if desired, the addition of the acid in several portionsresulting in the more eificient employment of the acid. For example,upon the familiar California base crude, I have employed first tenpounds of sulfuric acid of approximately 66 Baum in strength per barrelof Oll stock to be treated, and agitated the oil and acid to ether bycompressed air or other means or a period of one hour. The admixture wasthen allowed to settle for a period of time of approximately four. hoursand the resultant acid sludge drawn off. Thereafter a second portion often pounds of acid per barrel of stock was added to the oil stockand theadmixture again agitated for a period of a proximately one hour. Then inorder to e ect an efficient removal of all the sludge from the oil thereis preferably added 3% of water to the stock and the agitation continuedfor approximately five minutes so that the sludge from the acidtreatment would be properly coked, so that the finely divided sludgecould be removed scribed in my patent application filed May 14, 1925,Serial No. 30,356.

Subsequent to such reliminary acid treatment of lubricating .011 stock,the stock is neutralized by an alkaline neutralizing agent where acaustic soda solution is used, the caustic soda solution is supplied tothe oil hot and relatively weak. For example, to the oil stock is added8% by volume of caustic soda solution of 3 gravity with sufiicientboiling hot water to render the neutralizing solution hot. The admixtureis agitated until the alkali neutralizes all the acid present in theoil. This results not only sequent to such acid treatment, a further inan efiicient neutralization of the oil from all sulfuric acid reactionproducts, but also results in a neutralization and removal ofsubstantially all the organic acids therein present. During agitation ofthe neutralizing solution and oil, the admixture is maintained at atemperatureof approximately 160 F. Upon completion of the reaction, theadmixture is given a hot spray wash and permitted to settle. The alkalisolution is then withdrawn and the oil washed free from traces of thealkali solution. The neutralized oil is then freed from traces of waterby blowing air through the same or in any other preferred manner.

So far, the process of refining the lubricating oil stock is generallysimilar to the general process of manufacturing lubricating oils bysurfuric acid and caustic soda. As a result of such process, the oil isfreed from the majority of its organic acids. However, the heavy acidtreatment of the oil stock when followed by a neutralization withcaustic soda or other chemical neutralizing agent, is found to effect afixing in the Oil of certain constituents which impart to the 011 a bluefluorescence. The exact nature of such constituents is notdefinitelyknown, but it is generally recognized that the presence of asubstantially blue fluorescence indicates an inferior quality oflubricating oil. In order to free the lubricating oil from suchimpurities, the treated oil is again subjected to a sulfuric acidtreatment.

In this last sulfuric acid treatment; it is generally necessary to applyonly a relatively small quantity of acid, such as five pounds ofsulfuric acid per barrel of stock. The acid and oil are agitatedtogether in the usual manner and then permitted to settle and theresultant sludge withdrawn. Subquantity of the remaining suspendedfinely divided sludge is removed by adding as a coagulant a finelycomminuted solid absorbent material in proportions of one ton of suchmaterial to 30,000 gallons of stock under treatment, the same beingintimately admixed together for a period of about one hour. Thistreatment results in the removal of the major portionvof the finely di-"vided sludge which is left suspended within for example, of one ton ofsuch material to 5,000 gallons of stock under treatment. This admixtureis then agitated together while the stock is heated to a temperature ofover 250 F. and preferably to 300 F., in order to cause the colloidallyretained sludge to decompose and permit the same to be removed by thecomminuted solid material, as explained in the aforesaid copendingapplications. The oil is then filtered from the admixture and cooled.Subsequently, the oil is brightened by blowing with air in the usualmanner.

As a result of this second acid treatment and neutralization with acomminuted solid, the blue fluorescence imparted to the oil from thefirst acid treatment followed by the caustic soda neutralization hasbeen destroyed and an oil of the desired green fluorescence obtained,such oil being of extremely light and stable color and free of suchobjectionable compounds as may be removed by alkali or otherneutralizing agents.

lVhile a preferred example of a process embodying the present inventionhas been herein described in considerable detail for the purpose ofclearly illustrating the invention, it is to be understood thattheinvention is not limited to such details, but includes all suchmodifications and changes as come within the spirit of the followingappended claim.

I claim:

A process of manufacturing lubricating oil stock, which comprisestreating the oil stock with sulfuric acid, removing the sludge,neutralizing the stock with an alkaline substance, separating suchsubstance from the oil stock, thereafter applying further sul'- furicacid to the oil stock, settling and removing the formed sludge, thenagitating the oil stock with a comminuted solid adsorbent material at atemperature below that at which the sludge. decomposes to gather afurther quantity of the solid suspended sludge, separating the adsorbentmaterial with the matters adsorbed thereon from the oil stock, thenadding a comminuted solid adsorbent material to the oil stock, heatingthe admixture to a temperature suiiicient to decompose the remainingsludge and liberate sulfur dioxide therefrom, and separating theadsorbent material with the matters adsorbed thereon from the oil stock.

Signed at Los Angeles, Calif, this 30 day of October, 1925 JAMES W.'WEIR.

